package com.le.tester.imooc.masterJUC.collections.predecessor;

import java.util.HashMap;

/**
 * 描述：Map Demo
 */
public class MapDemo {
    public static void main(String[] args) {
        HashMap<String, Integer> map = new HashMap<>();
        System.out.println(map.isEmpty());
        map.put("e", 38);
        map.put("w", 28);
        System.out.println(map.keySet());
        System.out.println(map.containsKey("w"));
        map.remove("w");
        System.out.println(map.containsKey("w"));
    }
}
